diff --git a/macosx/Controller.m b/macosx/Controller.m
index 210ad6a0d..bc50fd482 100644
--- a/macosx/Controller.m
+++ b/macosx/Controller.m
@@ -1842,12 +1842,13 @@ static void sleepCallBack(void * controller, io_service_t y, natural_t messageTy
     {
         filtering = YES;
         
+        #warning check multiple trackers
         NSString * filterType = [fDefaults stringForKey: @"FilterSearchType"];
         NSString * fullString;
         Torrent * torrent;
         
         int i;
-        for (i = [tempTorrents count] - 1; i >= 0; i--)
+        for (i = [tempTorrents count]-1; i >= 0; i--)
         {
             torrent = [tempTorrents objectAtIndex: i];
             if ([filterType isEqualToString: FILTER_TYPE_TRACKER])
@@ -3034,7 +3035,7 @@ static void sleepCallBack(void * controller, io_service_t y, natural_t messageTy
 {
     NSEnumerator * enumerator;
     Torrent * torrent;
-    BOOL active;
+    BOOL active, canSleep;
 
     switch (messageType)
     {
@@ -3058,20 +3059,24 @@ static void sleepCallBack(void * controller, io_service_t y, natural_t messageTy
             break;
 
         case kIOMessageCanSystemSleep:
-            //pevent idle sleep unless all paused
-            active = NO;
-            enumerator = [fTorrents objectEnumerator];
-            while ((torrent = [enumerator nextObject]))
-                if ([torrent isActive] && ![torrent isStalled] && ![torrent isError])
-                {
-                    active = YES;
-                    break;
-                }
+            
+            canSleep = YES;
+            if ([fDefaults boolForKey: @"SleepPrevent"])
+            {
+                //prevent idle sleep unless all inactive
+                enumerator = [fTorrents objectEnumerator];
+                while ((torrent = [enumerator nextObject]))
+                    if ([torrent isActive] && ![torrent isStalled] && ![torrent isError])
+                    {
+                        canSleep = NO;
+                        break;
+                    }
+            }
 
-            if (active)
-                IOCancelPowerChange(fRootPort, (long) messageArgument);
-            else
+            if (canSleep)
                 IOAllowPowerChange(fRootPort, (long) messageArgument);
+            else
+                IOCancelPowerChange(fRootPort, (long) messageArgument);
             break;
 
         case kIOMessageSystemHasPoweredOn:
diff --git a/macosx/Defaults.plist b/macosx/Defaults.plist
index 0f17a9145..16dfe3632 100644
--- a/macosx/Defaults.plist
+++ b/macosx/Defaults.plist
@@ -84,6 +84,8 @@
 	<string>Submarine</string>
 	<key>ShowInspector</key>
 	<false/>
+    <key>SleepPrevent</key>
+	<true/>
 	<key>SmallStatusRegular</key>
 	<true/>
 	<key>SmallView</key>
diff --git a/macosx/English.lproj/PrefsWindow.nib/info.nib b/macosx/English.lproj/PrefsWindow.nib/info.nib
index c8ca51ff1..d5545df91 100644
--- a/macosx/English.lproj/PrefsWindow.nib/info.nib
+++ b/macosx/English.lproj/PrefsWindow.nib/info.nib
@@ -3,17 +3,17 @@
 <plist version="1.0">
 <dict>
 	<key>IBDocumentLocation</key>
-	<string>19 79 356 240 0 0 1152 842 </string>
+	<string>32 103 356 240 0 0 1680 1028 </string>
 	<key>IBEditorPositions</key>
 	<dict>
 		<key>153</key>
-		<string>294 444 563 268 0 0 1152 842 </string>
+		<string>558 568 583 268 0 0 1680 1028 </string>
 		<key>28</key>
-		<string>138 430 563 313 0 0 1152 842 </string>
+		<string>558 511 583 348 0 0 1680 1028 </string>
 		<key>41</key>
-		<string>294 426 563 305 0 0 1152 842 </string>
+		<string>548 550 583 305 0 0 1680 1028 </string>
 		<key>66</key>
-		<string>294 506 563 144 0 0 1152 842 </string>
+		<string>334 527 583 144 0 0 1680 1028 </string>
 	</dict>
 	<key>IBFramework Version</key>
 	<string>446.1</string>
@@ -23,9 +23,9 @@
 	</array>
 	<key>IBOpenObjects</key>
 	<array>
-		<integer>28</integer>
+		<integer>153</integer>
 	</array>
 	<key>IBSystem Version</key>
-	<string>8R218</string>
+	<string>8R4031</string>
 </dict>
 </plist>
diff --git a/macosx/English.lproj/PrefsWindow.nib/keyedobjects.nib b/macosx/English.lproj/PrefsWindow.nib/keyedobjects.nib
index 00d7a1734..2c4717afd 100644
Binary files a/macosx/English.lproj/PrefsWindow.nib/keyedobjects.nib and b/macosx/English.lproj/PrefsWindow.nib/keyedobjects.nib differ